Biggest question has already been asked; which island?I spent 6 months on the south island walking around. One of my favorite climbs has already been mentioned. avalanche peak. Stewart Island is worth a look as well. As are a number of places. But if you are on the north island other routes must be explored.

Also, if you are near Christchurch (South Island), drive up to Kaikoura and take one of the marine wildlife boat rides. You'll see a few different types of whales, the acrobatic dusky dolphins, the huge wandering albatross, other subantarctic birds and be in front of the great coastline the entire time. (photo 1-shows a shot from the boat with an albatross backdropped against the Kaikoura mountains)

Mount Cook area is also a real nice place worth spending a few days exploring (photos 1 and 2)

All great suggestions so far. Avalanche Peak is in Arthur's Pass National Park, which is pretty amazing. There are some great day hikes in the area as well as some backcountry huts (more primitive than our huts here in CO), so the options for some thru hikes are good. Check out www.softrock.co.nz , good beta on that site. This is my stomping ground during their winter at good 'ol Temple Basin Ski Field. If anyone is thinking of skiing in NZ this summer come say hey.

We're also headed to NZ but in a different time frame. Right now it looks like arriving end of May and staying through mid-June, then returning mid-July through the end of August. Probably not the best times for mountaineering, but any suggestions would be helpful. We're also interested in multi-day backpacking trips, even without summits. We'll have camping gear so huts aren't crucial.

We have friends in Christchurch and Queenstown so we're probably going to stick to the South Island, but there's no reason we couldn't make it up to the North Island if the climbing is better. I'm confident in our crampon/ice axe skills and we've had a little experience with two tools on somewhat vertical ice. We don't have glacier travel experience, although we're planning on practicing skills a bit this spring around Colorado... And we have no experience in building rock or ice protection.

That time of year, I'd suggest Abel Tasman. Kepler and Routeburn tracks are done that time of year too, but of course you have to go well prepared. Trekking up to Hooker Glacier in the Mt Cook area will be spectacular if you can hit it during good weather.

For summits without glacier travel, some possibilities would be Mt Luxmore on the South Island, and Taranaki, Ngauruhoe, Ruapehu, and Tongariro on the North Island.

If one is in Queenstown and wants a Bierstadt equivalent w/o the altitude and with 3000 ft. of vertical . . . couple of hours out . . . above treeline . . . with a view at the end . . . consider Ben Lomand. Perfect half day activity if the rest of the crew is doing the adrenaline gig or shopping, etc.